TPE material for refrigerator door seal and preparation method thereof

Abstract

The application belongs to the technical field of sealing materials, and particularly relates to a TPE material for refrigerator door sealing strips and a preparation method thereof. The TPE material for refrigerator door sealing strips comprises the following components in parts by weight: 20-40 parts of hydrogenated styrene-butadiene-styrene block copolymer, 5-10 parts of polyolefin, and 4-10 parts of a compatibilizer. The compatibilizer comprises a maleic anhydride grafted styrene-ethylene / butylene block copolymer. The TPE material for refrigerator door sealing strips has increased adhesion between different substances in the TPE material due to the introduction of the compatibilizer, thereby increasing the adhesion of the TPE material and improving the durability of the material.

Description

Technical Field

[0001] This invention belongs to the field of sealing material technology, specifically relating to a TPE material for refrigerator door seals and its preparation method. Background Technology

[0002] Refrigerator door seals are an important component of refrigerators. They effectively prevent cold air from escaping and hot air from entering, maintaining a stable internal temperature and reducing energy consumption. Most existing door seals are made of PVC (polyvinyl chloride), but this material is prone to aging and wear, requiring frequent replacement and increasing operating costs.

[0003] TPE (thermoplastic elastomer) is a new type of polymeric elastic material with excellent wear resistance, cold resistance, and chemical corrosion resistance, and is gradually being used in the manufacture of refrigerator door seals. However, some problems still exist with TPE materials currently on the market, such as poor weather resistance and easy wear, which require further improvement.

[0004] Therefore, in view of the above shortcomings, this invention is proposed. Summary of the Invention

[0005] The main objective of this invention is to propose a TPE material for refrigerator door seals and its preparation method. The TPE material for refrigerator door seals of this invention increases the bonding force between different substances in the TPE material due to the introduction of a compatibilizer, thereby increasing the adhesion of the TPE material and improving its durability.

[0006] To achieve the above objectives, the present invention provides the following technical solutions.

[0007] In a first aspect, the present invention provides a TPE material for refrigerator door seals, the TPE material comprising the following components in parts by weight: 20 to 40 parts of hydrogenated styrene-butadiene-styrene block copolymer, 5 to 10 parts of polyolefin, and 4 to 10 parts of compatibilizer, wherein the compatibilizer comprises maleic anhydride-grafted styrene-ethylene / butene block copolymer.

[0008] In some embodiments of the present invention, the grafting rate of the maleic anhydride is 0.8% to 3.0% by mass, based on the total mass of the maleic anhydride-grafted styrene-ethylene / butene block copolymer; and / or, the mass percentage of the styrene is 29% to 32%.

[0009] In some embodiments of the present invention, based on the total mass of the maleic anhydride-grafted styrene-ethylene / butene block copolymer, the mass percentage of volatile matter in the maleic anhydride-grafted styrene-ethylene / butene block copolymer is ≤0.5%; and / or, the mass percentage of ash in the maleic anhydride-grafted styrene-ethylene / butene block copolymer is ≤1.0%.

[0010] In some embodiments of the present invention, the melt flow index of the maleic anhydride-grafted styrene-ethylene / butene block copolymer is 3 g / min to 20 g / min; and / or, the specific gravity of the maleic anhydride-grafted styrene-ethylene / butene block copolymer is ≥0.89 g / cc.

[0011] In some embodiments of the present invention, the TPE material further includes 20 to 40 parts of lubricating oil.

[0012] In some embodiments of the present invention, the TPE material further includes 10 to 40 parts of talc powder.

[0013] In some embodiments of the present invention, the polyolefin includes one or more of polyethylene, polypropylene, propylene copolymer, poly-1-butene, poly-4-methyl-1-pentene, and cyclic olefin polymers.

[0014] In a second aspect, the present invention provides a method for preparing the TPE material for refrigerator door seals as described in the first aspect, the method comprising: mixing and granulating the constituent raw materials of the TPE material, and extruding the resulting TPE particles.

[0015] In some embodiments of the present invention, the temperature of the mixing and granulation is 145°C to 165°C, and the rotation speed is 20 r / min to 40 r / min.

[0016] In some embodiments of the present invention, the extrusion molding temperature is 145°C to 165°C and the rotation speed is 20 r / min to 40 r / min.

[0017] Compared with the prior art, the present invention achieves the following technical effects:

[0018] The TPE material used for refrigerator door seals of the present invention has increased adhesion between different substances in the TPE material due to the introduction of a compatibilizer, thus increasing the adhesion of the TPE material and making it more durable when used as a door seal material.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0020] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. In the drawings:

[0021] Figure 1 This is a process flow diagram of a method for preparing TPE material for refrigerator door seals according to some embodiments of the present invention. Detailed Implementation

[0022] Exemplary embodiments of the present invention will now be described in more detail with reference to specific examples. It should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0024] In the description of the embodiments of the present invention, the technical terms "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0025] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0026] In the description of the embodiments of this invention, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0027] In the description of the embodiments of the present invention, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0028] Existing TPE refrigerator door seals suffer from insufficient adhesion and poor durability. This is mainly because TPE materials are mostly composed of multi-component thermoplastic elastomers and additives. The material composition and processing significantly impact the cost and performance of TPE. Although some polymer adhesives are currently used on the market, their effectiveness is not ideal. Strengthening the adhesion of TPE materials remains a crucial approach to improving their durability.

[0029] This invention provides a TPE material for refrigerator door seals, comprising the following components by weight: 20-40 parts of hydrogenated styrene-butadiene-styrene block copolymer (SEBS thermoplastic elastomer), 5-10 parts of polyolefin, and 4-10 parts of compatibilizer; wherein the compatibilizer includes maleic anhydride-grafted styrene-ethylene / butene block copolymer. Due to the introduction of the compatibilizer, the TPE material of this invention increases the adhesion between different substances in the TPE raw material, thereby increasing the TPE's adhesive strength and making it more durable when used as a refrigerator door seal material.

[0030] In the TPE material provided by this invention, the weight parts of the hydrogenated styrene-butadiene-styrene block copolymer can be any value within the range formed by any two values ​​in the above-mentioned range, such as 20 parts to 30 parts, or 30 parts to 40 parts, and so on. The weight parts of the hydrogenated styrene-butadiene-styrene block copolymer provided by this invention can also be one of 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, or 40 parts, or any value satisfying the above-mentioned range.

[0031] In the TPE material provided by this invention, the weight parts of polyolefin can be any value within the range formed by any two values ​​in the above-mentioned range, such as 5 parts to 7 parts, or 7 parts to 10 parts, and so on. The weight parts of polyolefin provided by this invention can also be one of 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts, or any value that satisfies the above-mentioned range.

[0032] In some embodiments of the present invention, the polyolefin includes one or more of polyethylene, polypropylene, propylene copolymer, poly-1-butene, poly-4-methyl-1-pentene, or cycloolefin polymers.

[0033] In the TPE material provided by this invention, the weight parts of the compatibilizer can be any value within the range formed by any two values ​​in the above-mentioned range, such as 4 to 6 parts, or 6 to 10 parts, and so on. The weight parts of the compatibilizer provided by this invention can also be one of 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts, or any value that satisfies the above-mentioned range.

[0034] In some embodiments of the present invention, the compatibilizer is a maleic anhydride-grafted styrene-ethylene / butene block copolymer, and the grafting rate of maleic anhydride, based on the total mass of the maleic anhydride-grafted styrene-ethylene / butene block copolymer, is 0.8% to 3.0% by mass percentage. Exemplarily, the mass percentage of the maleic anhydride grafting rate can be a value within the range formed by any two values ​​within the above-mentioned range, such as 0.8% to 1.6%, or 1.6% to 3.0%, and so on. The mass percentage of the maleic anhydride grafting rate can also be one of 0.8%, 0.9%, 1.0%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, 2.0%, 2.2%, 2.4%, 2.5%, 2.6%, 2.8%, and 3.0%, or any value satisfying the above-mentioned range.

[0035] In some embodiments of the present invention, the mass percentage of styrene is 29% to 32% based on the total mass of the maleic anhydride-grafted styrene-ethylene / butene block copolymer. Exemplarily, the mass percentage of styrene can be one of 29%, 30%, 31%, 32%, or any value satisfying the above range.

[0036] In some embodiments of the present invention, based on the total mass of the maleic anhydride-grafted styrene-ethylene / butene block copolymer, the mass percentage of volatiles in the maleic anhydride-grafted styrene-ethylene / butene block copolymer is ≤0.5%. Exemplarily, the mass percentage of volatiles can be one of 0.01%, 0.02%, 0.04%, 0.05%, 0.06%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, or any value satisfying the above range.

[0037] In some embodiments of the present invention, based on the total mass of the maleic anhydride-grafted styrene-ethylene / butene block copolymer, the mass percentage of ash in the maleic anhydride-grafted styrene-ethylene / butene block copolymer is ≤1.0%. Exemplarily, the mass percentage of ash can be one of 0.01%, 0.02%, 0.04%, 0.05%, 0.06%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or any value satisfying the above range.

[0038] In some embodiments of the present invention, the melt flow index of the maleic anhydride-grafted styrene-ethylene / butene block copolymer is 3 g / min to 20 g / min. Exemplarily, the melt flow index can be any value within the range of any two values ​​described above, such as 3 g / min to 10 g / min, or 10 g / min to 20 g / min, and so on. The melt flow index can also be one of 3 g / min, 4 g / min, 5 g / min, 6 g / min, 7 g / min, 8 g / min, 9 g / min, 10 g / min, 11 g / min, 12 g / min, 13 g / min, 14 g / min, 15 g / min, 16 g / min, 17 g / min, 18 g / min, 19 g / min, and 20 g / min, or any value satisfying the above range.

[0039] In some embodiments of the present invention, the specific gravity of the maleic anhydride-grafted styrene-ethylene / butene block copolymer is ≥0.89 g / cc.

[0040] In embodiments of the present invention, the TPE material for the refrigerator door seal of the present invention further includes 20 to 40 parts of lubricating oil. Exemplarily, the weight percentage of the lubricating oil of the present invention can be any value within the range formed by any two values ​​within the above-mentioned range, such as 20 to 30 parts, 30 to 40 parts, and so on. The weight percentage of the lubricating oil of the present invention can also be one of 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 parts, or any value satisfying the above-mentioned range.

[0041] In some embodiments of the present invention, the lubricating oil is selected from one or more of stearic acid, paraffin wax, and polyethylene wax.

[0042] In embodiments of the present invention, the TPE material for the refrigerator door seal of the present invention further includes 10 to 40 parts of talc powder. Exemplarily, the weight parts of talc powder of the present invention can be any value within the range formed by any two values ​​in the above-mentioned range, such as 10 to 20 parts, or 20 to 40 parts, and so on. The weight parts of talc powder of the present invention can also be one of 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 parts, or any value satisfying the above-mentioned range.

[0043] In an embodiment of the invention, the TPE material for the refrigerator door seal comprises the following components by weight: 20 to 40 parts of hydrogenated styrene-butadiene-styrene block copolymer, 5 to 10 parts of polyolefin, 4 to 10 parts of compatibilizer, 10 to 40 parts of talc, and 20 to 40 parts of lubricating oil.

[0044] The present invention also provides a method for preparing TPE material for refrigerator door seals. The preparation method can be to obtain TPE granules by high mixing of raw materials and extrusion, and then produce door seals by door seal extrusion molding process.

[0045] The preparation method of TPE material for refrigerator door seals in this invention includes the following steps.

[0046] (1) Mixing raw materials.

[0047] In some embodiments of the present invention, the constituent raw materials are mixed evenly according to a preset weight ratio.

[0048] In some embodiments of the present invention, the raw materials are added into a high-speed mixer in proportion to their weight and stirred until uniform.

[0049] (2) Granulation.

[0050] In an embodiment of the present invention, the uniformly mixed material obtained in step (1) is fed into a granulator for blending and granulation to obtain TPE particles.

[0051] In some embodiments of the present invention, the mixing and granulation temperature is 145℃~165℃, and the rotation speed is 20r / min~40r / min. The granulation temperature provided by the present invention can be one of 145℃, 150℃, 155℃, 160℃, and 165℃, or any value satisfying the above range. The rotation speed provided by the present invention can be one of 20r / min, 21r / min, 22r / min, 23r / min, 24r / min, 25r / min, 26r / min, 27r / min, 28r / min, 29r / min, 30r / min, 31r / min, 32r / min, 33r / min, 34r / min, 35r / min, 36r / min, 37r / min, 38r / min, 39r / min, and 40r / min, or any value satisfying the above range.

[0052] In some embodiments of the invention, a twin-screw extruder is used for mixing and granulation.

[0053] It is worth mentioning that the pellet mill can be preheated before feeding the well-mixed material into the pellet mill, such as by heating it to the pelleting temperature.

[0054] In some embodiments of the invention, the pelletizer is equipped with cooling and pelletizing devices.

[0055] (3) Extrusion molding.

[0056] In an embodiment of the present invention, the TPE particles obtained in step (3) are fed into an extruder and extruded to obtain TPE material for refrigerator door seals.

[0057] In some embodiments of the present invention, the extrusion molding temperature is 145℃~165℃, and the rotation speed is 20r / min~40r / min. The extrusion molding temperature provided by the present invention can be one of 145℃, 150℃, 155℃, 160℃, and 165℃, or any value satisfying the above range. The rotation speed provided by the present invention can be one of 20r / min, 21r / min, 22r / min, 23r / min, 24r / min, 25r / min, 26r / min, 27r / min, 28r / min, 29r / min, 30r / min, 31r / min, 32r / min, 33r / min, 34r / min, 35r / min, 36r / min, 37r / min, 38r / min, 39r / min, and 40r / min, or any value satisfying the above range.

[0058] In some embodiments of the present invention, a twin-screw door seal extruder is used for extrusion molding.

[0059] It is worth mentioning that the extruder can be preheated before the TPE particles prepared in the granulation process are fed into the extruder, such as by heating it to the extrusion temperature.

[0060] In some embodiments of the invention, the extruder is equipped with an extrusion, shaping, and cutting die that matches the required door seal cross-section.

[0061] In some embodiments of the invention, the extruder is also equipped with a cooling spray and drying device. For example, a spray-type traction cooling device.

[0062] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are all conventional biochemical reagents; the raw materials, instruments, and equipment used in the following embodiments can all be obtained commercially or through existing methods; unless otherwise specified, the amounts of experimental reagents used are the amounts used in conventional experimental operations; unless otherwise specified, the experimental methods are all conventional methods.

[0063] Example 1

[0064] A TPE material for refrigerator door seals and its preparation method are disclosed. The TPE material comprises the following components by weight: 30 parts hydrogenated styrene-butadiene-styrene block copolymer, 8 parts polyethylene, 8 parts compatibilizer, 30 parts stearic acid as a lubricant, and 24 parts talc. The compatibilizer is a maleic anhydride-grafted styrene-ethylene / butene block copolymer produced by Shanghai Tengyu Polymer Materials Co., Ltd., with the following parameters:

[0065] Table 1

[0066] Test Items Test Results Styrene content 30％ proportion 0.90g / cc maleic anhydride grafting rate 2.0Wt% Volatile matter ≤0.5％ Ash ≤1.0％ Melt Flow Index 16g / min

[0067] like Figure 1 As shown, the preparation method of TPE material for refrigerator door seals is as follows:

[0068] (1) Raw material mixing: Put the above raw materials into a high-speed mixer and stir for 8 minutes to obtain a uniformly mixed mixture.

[0069] (2) Blending and granulation: The mixture is fed into a preheated twin-screw extruder for blending and granulation to obtain TPE particles. The granulator temperature is 150℃ and the granulator speed is 30r / min.

[0070] (3) Extrusion of door seal: TPE particles are fed into a preheated twin-screw door seal extruder to extrude the door seal. The extruder temperature is 150℃ and the speed of the extruder is 30r / min. Then, the door seal is formed by traction cooling.

[0071] Example 2

[0072] Except for the following differences, the preparation was carried out in the same manner as in Example 1:

[0073] The TPE material used for refrigerator door seals comprises the following components by weight: 40 parts hydrogenated styrene-butadiene-styrene block copolymer, 5 parts polypropylene, 10 parts compatibilizer, 20 parts paraffin wax as lubricant, and 25 parts talc.

[0074] Example 3

[0075] Except for the following differences, the preparation was carried out in the same manner as in Example 1:

[0076] The TPE material for refrigerator door seals comprises the following components by weight: 36 parts hydrogenated styrene-butadiene-styrene block copolymer, 10 parts poly-1-butene, 4 parts compatibilizer, 40 parts polyethylene wax as lubricant, and 10 parts talc.

[0077] Comparative Example 1

[0078] Except for the following differences, the preparation was carried out in the same manner as in Example 1:

[0079] 40 parts of hydrogenated styrene-butadiene-styrene block copolymer, 10 parts of polyolefin, 2 parts of compatibilizer, 3 parts of stearic acid as lubricant, and 35 parts of calcium carbonate powder.

[0080] Performance testing

[0081] Adhesion strength: The refrigerator door seals prepared in the examples and comparative examples were molded into 2.0mm thick 150*40mm rectangular plates using TPE material through injection molding or compression molding. These rectangular plates were then bonded to an aluminum base plate using hot melt adhesive (hot pressing temperature 150℃, hot pressing time 2min). The adhesion strength was tested using a universal testing machine. The force during the peeling process was measured and recorded. A higher value indicates greater peel strength.

[0082] Weather resistance: In accordance with the provisions of GB / T 3511-2018 and GB / T16422.2-2014, the specimens were irradiated for 168 hours, and the percentage of tensile strength retention was tested and calculated, in %.

[0083] High and low temperature resistance test: The refrigerator door seals prepared in the examples and comparative examples were placed in an environment of 100°C for 5 hours, and then placed in an environment of 20°C for 5 hours, and the cycle was repeated 100 times. The performance retention percentage of tensile strength was tested and calculated, in units of %.

[0084] Tensile strength and elongation at break: The tensile strength and elongation at break of the products prepared in the above examples and comparative examples were tested according to the methods of GB / T 1040.12006 and GB / T 1040.32006, with a tensile speed of 100 mm / min.

[0085] The test results are as follows:

[0086] Table 2

[0087]

[0088]

[0089] This invention increases the bonding force between different substances in TPE raw materials by introducing maleic anhydride grafted with styrene-ethylene / butene block copolymer as a compatibilizer, thereby increasing the bonding force of TPE and making it more durable when used as a raw material for refrigerator door seals.

[0090] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A TPE material for refrigerator door seals, characterized in that, Includes the following components by weight: 20-40 parts hydrogenated styrene-butadiene-styrene block copolymer, 5-10 parts polyolefin, 4-10 parts compatibilizer The compatibilizer includes a maleic anhydride-grafted styrene-ethylene / butene block copolymer.

2. The TPE material for refrigerator door seals as described in claim 1, characterized in that, Based on the total mass of the maleic anhydride-grafted styrene-ethylene / butene block copolymer, the grafting rate of the maleic anhydride is 0.8% to 3.0% by mass; and / or, The styrene content is 29% to 32% by mass.

3. The TPE material for refrigerator door seals as described in claim 1 or 2, characterized in that, Based on the total mass of the maleic anhydride-grafted styrene-ethylene / butene block copolymer, the mass percentage of volatile matter in the maleic anhydride-grafted styrene-ethylene / butene block copolymer is ≤0.5%; and / or, The mass percentage of ash in the maleic anhydride-grafted styrene-ethylene / butene block copolymer is ≤1.0%.

4. The TPE material for refrigerator door seals as described in claim 1 or 2, characterized in that, The melt flow index of the maleic anhydride-grafted styrene-ethylene / butene block copolymer is 3 g / min to 20 g / min; and / or, The specific gravity of the maleic anhydride-grafted styrene-ethylene / butene block copolymer is ≥0.89 g / cc.

5. The TPE material for refrigerator door seals as described in claim 1, characterized in that, The TPE material also includes: 20 to 40 parts of lubricating oil.

6. The TPE material for refrigerator door seals as described in claim 1, characterized in that, The TPE material also includes 10 to 40 parts of talc.

7. The TPE material for refrigerator door seals as described in claim 1, characterized in that, The polyolefin includes one or more of polyethylene, polypropylene, propylene copolymer, poly-1-butene, poly-4-methyl-1-pentene, and cyclic olefin polymers.

8. A method for preparing a TPE material for a refrigerator door seal according to any one of claims 1-7, characterized in that, The preparation method includes: The raw materials of TPE material are mixed and granulated, and the resulting TPE particles are extruded and molded.

9. The preparation method according to claim 8, characterized in that, The mixing and granulation temperature is 145℃~165℃, and the rotation speed is 20r / min~40r / min.

10. The preparation method according to claim 8, characterized in that, The extrusion molding temperature is 145℃~165℃, and the rotation speed is 20r / min~40r / min.

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